NotBlank

Validates that a value is not blank - meaning not equal to a blank string, a blank array, false or null (null behavior is configurable). To check that a value is not equal to null, see the NotNull constraint.

Applies to	property or method
Class	NotBlank
Validator	NotBlankValidator

Basic Usage

If you wanted to ensure that the firstName property of an Author class were not blank, you could do the following:

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        // src/Entity/Author.php
namespace App\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    #[Assert\NotBlank]
    protected string $firstName;
}
    

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        # config/validator/validation.yaml
App\Entity\Author:
    properties:
        firstName:
            - NotBlank: ~
    

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        <!-- config/validator/validation.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">

    <class name="App\Entity\Author">
        <property name="firstName">
            <constraint name="NotBlank"/>
        </property>
    </class>
</constraint-mapping>
    

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        // src/Entity/Author.php
namespace App\Entity;

use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Mapping\ClassMetadata;

class Author
{
    // ...

    public static function loadValidatorMetadata(ClassMetadata $metadata): void
    {
        $metadata->addPropertyConstraint('firstName', new Assert\NotBlank());
    }
}
    

Options

`allowNull`

type: boolean default: false

If set to true, null values are considered valid and won't trigger a constraint violation.

`groups`

type: array | string default: null

It defines the validation group or groups of this constraint. Read more about validation groups.

`message`

type: string default: This value should not be blank.

This is the message that will be shown if the value is blank.

You can use the following parameters in this message:

Parameter	Description
`{{ value }}`	The current (invalid) value
`{{ label }}`	Corresponding form field label

`normalizer`

type: a PHP callable default: null

This option allows to define the PHP callable applied to the given value before checking if it is valid.

For example, you may want to pass the 'trim' string to apply the trim PHP function in order to ignore leading and trailing whitespace during validation.

`payload`

type: mixed default: null

This option can be used to attach arbitrary domain-specific data to a constraint. The configured payload is not used by the Validator component, but its processing is completely up to you.

For example, you may want to use several error levels to present failed constraints differently in the front-end depending on the severity of the error.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.

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